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Posted to commits@trafficserver.apache.org by zw...@apache.org on 2019/11/19 06:28:14 UTC
[trafficserver] 01/02: Add basic SystemTap markers support
This is an automated email from the ASF dual-hosted git repository.
zwoop pushed a commit to branch 9.0.x
in repository https://gitbox.apache.org/repos/asf/trafficserver.git
commit c7e32a84eb724e45a6ef18e55aa9a41e4b71a644
Author: Emanuele Rocca <em...@wikimedia.org>
AuthorDate: Thu Oct 10 13:48:43 2019 -0700
Add basic SystemTap markers support
Introduce a new ./configure flag, --enable-systemtap, to build
traffic_server with SystemTap markers support. Also include a marker
called "new_origin_server_connection" under the "trafficserver"
provider.
See https://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps
(cherry picked from commit dd27599720cfccbfd77fa20e47f529fa972d0469)
---
configure.ac | 19 +++++++++++
doc/developer-guide/debugging/debug-builds.en.rst | 19 +++++++++++
doc/release-notes/whats-new.en.rst | 1 +
include/ts/sdt.h | 40 +++++++++++++++++++++++
proxy/http/HttpSM.cc | 3 ++
5 files changed, 82 insertions(+)
diff --git a/configure.ac b/configure.ac
index 8a9bb93..c03c6df 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2085,6 +2085,25 @@ AC_CHECK_TYPE([struct tcp_info],
]]
)
+AC_MSG_CHECKING([whether to include systemtap tracing support])
+AC_ARG_ENABLE([systemtap],
+ [AS_HELP_STRING([--enable-systemtap],
+ [Enable inclusion of systemtap trace support])],
+ [ENABLE_SYSTEMTAP="${enableval}"], [ENABLE_SYSTEMTAP='no'])
+AM_CONDITIONAL([ENABLE_SYSTEMTAP], [test x$ENABLE_SYSTEMTAP = xyes])
+AC_MSG_RESULT(${ENABLE_SYSTEMTAP})
+
+if test "x${ENABLE_SYSTEMTAP}" = xyes; then
+ AC_CHECK_PROGS(DTRACE, dtrace)
+ if test -z "$DTRACE"; then
+ AC_MSG_ERROR([dtrace not found])
+ fi
+ AC_CHECK_HEADER([sys/sdt.h], [SDT_H_FOUND='yes'],
+ [SDT_H_FOUND='no';
+ AC_MSG_ERROR([systemtap support needs sys/sdt.h header])])
+ AC_DEFINE([HAVE_SYSTEMTAP], [1], [Define to 1 if using probes.])
+fi
+
# See if we can build the remap_stats plugin
AS_IF([test "x$enable_experimental_plugins" = "xyes"],
[
diff --git a/doc/developer-guide/debugging/debug-builds.en.rst b/doc/developer-guide/debugging/debug-builds.en.rst
index 53ad22c..d1e823f 100644
--- a/doc/developer-guide/debugging/debug-builds.en.rst
+++ b/doc/developer-guide/debugging/debug-builds.en.rst
@@ -41,3 +41,22 @@ Debugging Tips:
- Use assertions in your plugin (:c:func:`TSAssert` and :c:func:`TSReleaseAssert`).
+SystemTap and DTrace support
+****************************
+
+Traffic Server can be instrumented with **SystemTap** on Linux systems, or
+**DTrace** on *BSDs and macOS. In order to use such tools, Traffic Server needs
+to be built with ``-g``, or the debug symbols need to be installed. On Debian
+systems, install the ``trafficserver-dbgsym`` package to install the debug
+symbols.
+
+In addition to the normal probe points that can be used with SystemTap and
+DTrace, such as function calls and specific statements, Traffic Server does
+provide SDT markers at various interesting code paths.
+
+Pass the ``--enable-systemtap`` flag to ``./configure`` in order to build
+Traffic Server with dtrace style markers (SDT). On Traffic Server builds with
+SDT markers enabled, you can list the available markers with ``stap -L
+'process("/path/to/traffic_server").mark("*")``.
+
+See the `SystemTap documentation <https://sourceware.org/systemtap/wiki/AddingUserSpaceProbingToApps>`_ and the `DTrace guide <http://dtrace.org/guide/chp-sdt.html>`_ for more information.
diff --git a/doc/release-notes/whats-new.en.rst b/doc/release-notes/whats-new.en.rst
index 93486a0..4ddf378 100644
--- a/doc/release-notes/whats-new.en.rst
+++ b/doc/release-notes/whats-new.en.rst
@@ -29,6 +29,7 @@ of <z> contributors have participated in this development cycle.
New Features
------------
+- Add support for dtrace style markers (SDT) and include a few markers at locations of interest to users of SystemTap, dtrace, and gdb. See :ref:`developer-debug-builds`.
This version of ATS has a number of new features (details below), but we're
particularly excited about the following features:
diff --git a/include/ts/sdt.h b/include/ts/sdt.h
new file mode 100644
index 0000000..68f8d92
--- /dev/null
+++ b/include/ts/sdt.h
@@ -0,0 +1,40 @@
+/** @file
+
+ A brief file description
+
+ @section license License
+
+ Licensed to the Apache Software Foundation (ASF) under one
+ or more contributor license agreements. See the NOTICE file
+ distributed with this work for additional information
+ regarding copyright ownership. The ASF licenses this file
+ to you under the Apache License, Version 2.0 (the
+ "License"); you may not use this file except in compliance
+ with the License. You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+
+#pragma once
+
+#ifdef HAVE_SYSTEMTAP
+
+#include <sys/sdt.h>
+
+#define ATS_PROBE(probe) DTRACE_PROBE(trafficserver, probe)
+#define ATS_PROBE1(probe, param1) DTRACE_PROBE1(trafficserver, probe, param1)
+#define ATS_PROBE2(probe, param1, param2) DTRACE_PROBE2(trafficserver, probe, param1, param2)
+
+#else
+
+#define ATS_PROBE(...)
+#define ATS_PROBE1(...)
+#define ATS_PROBE2(...)
+
+#endif
diff --git a/proxy/http/HttpSM.cc b/proxy/http/HttpSM.cc
index 9f3eb4b..45d3e5b 100644
--- a/proxy/http/HttpSM.cc
+++ b/proxy/http/HttpSM.cc
@@ -44,6 +44,7 @@
#include "IPAllow.h"
#include "tscore/I_Layout.h"
#include "tscore/bwf_std_format.h"
+#include "ts/sdt.h"
#include <openssl/ossl_typ.h>
#include <openssl/ssl.h>
@@ -1712,6 +1713,8 @@ HttpSM::state_http_server_open(int event, void *data)
session->new_connection(vc);
+ ATS_PROBE1(new_origin_server_connection, t_state.current.server->name);
+
session->state = HSS_ACTIVE;
ats_ip_copy(&t_state.server_info.src_addr, netvc->get_local_addr());